Square cake construction question

I have a customer requesting a three-tier square wedding cake with spaces in between each layer to add flowers. I have been wanting to get this Wilton Towering Tiers cake stand:

http://www.wilton.com/store/site/product.cfm?sku=pg_toweringtiers

Has anyone used this for square cakes? Do they make square plates for this, or should I just use a couple extra layers of cake board or foam core so the edges of the cake that would hang over the support don't sag?

Or is there another method that is better? She doesn't want visible pillars

There are square cake plates. Each inside tier will have 4 columns & 2plates, 1 plate under the cake , 1 plate on top of the tier thc cake is sitting on. I always ask to have the flower shd wants in between each layer because the head size of the flower determines what length column I need .

Wilton s site carry those interlocking plates and columns. If u measure thr width of the flower head you will know which column set to buy.

There are square cake plates. Each inside tier will have 4 columns & 2plates, 1 plate under the cake , 1 plate on top of the tier thc cake is sitting on. I always ask to have the flower shd wants in between each layer because the head size of the flower determines what length column I need .

Wilton s site carry those interlocking plates and columns. If u measure thr width of the flower head you will know which column set to buy.

There are square cake plates. Each inside tier will have 4 columns & 2plates, 1 plate under the cake , 1 plate on top of the tier thc cake is sitting on. I always ask to have the flower shd wants in between each layer because the head size of the flower determines what length column I need .

Wilton s site carry those interlocking plates and columns. If u measure thr width of the flower head you will know which column set to buy.

There are square cake plates. Each inside tier will have 4 columns & 2plates, 1 plate under the cake , 1 plate on top of the tier thc cake is sitting on. I always ask to have the flower shd wants in between each layer because the head size of the flower determines what length column I need .

Wilton s site carry those interlocking plates and columns. If u measure thr width of the flower head you will know which column set to buy.

There are square cake plates. Each inside tier will have 4 columns & 2plates, 1 plate under the cake , 1 plate on top of the tier thc cake is sitting on. I always ask to have the flower shd wants in between each layer because the head size of the flower determines what length column I need .

Wilton s site carry those interlocking plates and columns. If u measure thr width of the flower head you will know which column set to buy.